Joined: 03 Jun 2012
| Posted: Sun Feb 09, 2014 12:32 am Post subject: 2015 GSKA Clone Engine Rules
|Listed below are the 2015 Clone engine rules.
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2015 GSKA Box Stock Clone Rulebook
Rev. 1 11/19/2014
Section 1 - Engine Rules (apply to all classes):
1.1 Fuel: 87 octane pump fuel purchased on race day from Ingles Fuel Express at 625 Hwy. 341 South in Barnesville. Race officials will obtain a race day control sample to be used as the reference sample for fuel testing. Fuel tech will consist of zeroing a Digitron meter with the control sample. Competitors fuel must test within +/- 10 points of reference sample.
1.2 Oil: Any commercially available oil No additives allowed
i) Kid, Sportsman, and Junior Classes: Must be a shoe type clutch. Drum may be stamped or billet steel. No cooling fins may be either machined into the drum or added in any other manner. Disc clutches are not allowed.
ii) Senior Classes: Senior classes may run any dry clutch
1.4 Fuel Tank Requirements: Floor Mounted fuel tank required (stock tank to be removed).
1.5 Carburetor: Huayi or Rui*ing only. All stock gaskets must be present. Choke assembly must be functioning, cannot be altered, and must remain flat. Choke bore must remain as cast.
Venturi - .615 NO-GO
Rear carb bore - .751 NO-GO
Emulsion tube STOCK - .066 NO-GO (cannot pass all the way through)
Main jet - .042 NO-GO
Low speed idle jet Non tech item jet may not be drilled through to outside air
Throttle shaft - .115 minimum
Butterfly - .037 minimum butterfly screw must remain stock
1.6 Fuel Pump: Any pulse type fuel pump allowed. Fuel pump must be pulsed from valve cover.
1.7 Air Filter: Aftermarket air filter adapters are allowed. maximum length 1.375. Loss of air filter during a race does not constitute a reason for disqualification.
1.8 Block: Block must remain stock. Maximum bore is 2.685. Stroke is 2.123 plus .010 or minus .005. No pop-up allowed. Mating surfaces of block and cylinder head are non-tech items. Surfacing of both to correct for gasket failure and meet cc check is allowed. No welding on block.
1.9 Cylinder head: No porting, grinding, or modification. Valve seats have two or three angles. Two angle valve seats must have a 30 top and a 45 valve face. Three angle valve seats have angles of 30 at the top, 45 at the valve face, and 60 at the base. Intake seat .897maximum. Exhaust seat .862 maximum. Head gasket must be stock configuration. Gasket must be steel; copper or aluminum not allowed. Minimum head gasket thickness .008. One or two head gaskets are allowed with no maximum thickness. Sealer may be used.
1.10 Combustion chamber volume: Minimum volume 26.5cc as measured through the spark plug hole using the LAD tool and with the head on the engine.
1.11 Valve Train: Valve train will remain stock. No polishing. No grinding. No alterations. Stock OEM rocker arms only. Stock valve springs only. Maximum wire diameter is .071. Maximum spring pressure is 10.8 lbs at height of .850. Spring retainer measurements exhaust .250 MIN; intake .230 MIN. Intake valve diameter .985 +/- .005 with 45 angle. Exhaust valve diameter .948 +/- .005 with 45 angle. Lash cap on exhaust valve only. Valve stem seals are optional on intake and exhaust valves. Seal lip .027 maximum. Stock lifters. Minimum valve installed height is .815. Valve spring shims are allowed.
1.12 Connecting Rod: Stock rod only; Rod may be honed. No other modifications are allowed.
1.13 Piston and Rings: Stock pistons and rings only
1.14 Crankshaft: Stock crankshaft only; no modifications. Crankshaft journal is 1.180 maximum and 1.168 minimum
1.15 Camshaft: Camshaft must meet these specifications. Maximum running lift on exhaust is .242 taken on valve spring retainer with zero lash. Maximum running lift on intake is .238 taken on valve spring retainer with zero lash. Intake lift at the push rod is .225 maximum and .215 minimum. Exhaust lift at the push rod is .232 maximum and .222 minimum. Duration check for intake and exhaust lobes. Intake duration of 218.5 at .050 lift and 85.5 at .200 lift. Exhaust duration of 221.5 at .050 lift and 96.5 at .200 lift. (All checks will allow +2 degrees for wear and gauge variances)
1.16 Flywheel and Ignition: The Following flywheels are the only approved flywheels: (1) ARC Model 6619, (2) PVL, (3) Raceseng REV WHEEL FINNED S1. All at a minimum weight of 3 pounds, 2 ounces. The Speed Karts Steel Billet S1 flywheel is also approved at a minimum weight of 5 pounds, 3 ounces. The stock flywheel is no longer approved and may not be used. No machining or alternations of any kind are allowed. Ignition coil must be stock, but ignition timing is non-tech. The flywheel may be run with or without a key.
1.17 Header Pipe: Exhaust pipe/header must not have exposed sharp edges. Header/exhaust pipe must be wrapped if the pipe design exposes the driver to burns. Studs allowed for header pipe attachment to block. Header/exhaust pipe MAY NOT protrude into exhaust port.
(1) Kid, Sportsman, Junior, and Senior Option 1 Classes: Single stage pipe with maximum .750 outside diameter and .635 ID inside measurement. Maximum length on header and muffler is 15 and minimum is 10. No aftermarket coatings of any type allowed.
(2) Senior Option 2 Classes: Aftermarket coatings allowed.
1.18 Muffler: No aftermarket coatings of any type allowed
(1) Kid, Sportsman, Junior, and Senior Option 1 Classes: Muffler must be RLV Mini 91 Box Stock Threaded Nipple. No grinding or seam cleanup allowed. ID is .685 +/- .005. Rear baffle holes maximum ID is .1285. Inner baffle holes maximum ID is .0965. Muffler must be screwed on end of header pipe, not welded.
(2) Senior Option 2 Classes: Muffler must be a RV 91L type with .1285 no-go holes.
1.19 Starter: Pull starter must be present and remain stock. Pull starter may be rotated for a better cranking angle.
1.20 Engine oil recovery system: Functional engine oil recovery system (catch can) is mandatory
1.21 Oil Sensor: Oil sensor may be removed.
1.22 Governor: Governor and governor components are non-tech
1.23 Side cover gaskets: 2 gaskets maximum. Studs may be used on side cover.
1.24 Aftermarket Coatings: No aftermarket coatings of any type allowed except on blower housing shroud.
1.25 Sheet Metal: All sheet metal must be used as supplied with the engine.
1.26 Rules Revisions: It is GSKAs intention to freeze the above rules for the entire 2015 race season. Exceptions would be a safety issue or parts availability issue.
Rev. 1 11/19/2014 Initial 2015 rules as proposed
Download 2014 rules (for reference) Here
Download 2013 rules (for reference) Here
Download 2012 rules (for reference) Here
Download 2011 rules (for reference) Here
Download 2010 rules (for reference) Here
Download 2009 rules (for reference) Here